Warren spear mayo



Patented Aug. 5, 1890. 1

W. S. MAYO.

DRYING KILN.

(No Model.)

. W/T/VESSES: @f

, UNITED STATES PAJrENT OFFICE.

wARREN sPEAR MAYO, OE OTTAWA, ONTARIO, CANADA, AssreNoR OE ONE-HALE TO GEORGE RonERTsON, OEsAME PLACE.

DRYING-eKILN.

SPECIFICATION forming part of Letters Patent No. 433,800, dated August 5, '1890.

Application filed February 14, 1890. Serial No. 340,439. (No model.)

To all whom t may concern,.-

Be it known that I, VARREN SPEAR MAYO, a citizen of Canada, residing at Ottawa, in the county of Carlton andProvince of Ontario, Canada, have invented certain new and useful Improvements in Dry-Kilns, of which the following is a full, clear, and exact description.

The object of my invention is to provide a kiln especially adapted for drying lumber or saw-mill edgings, slats, dto., to be used as fuel.

The principalobj ects sought are to provide for the carrying of the material to and fro through a drying-chamber with a minimum expenditure of power, to maintain the separation of the boards or strips during their course of travel, and to turn them over repeatedly in such manner that they are sub-` jected on two sides to the action of the ascending currents of air.

To this end the invention consists in the combination of toothed endless conveyerchains arranged in inclined as distinguished from horizontal positions, in combination with stationary supporting rails or slats underlying the chains in inclined positions and extended upward around the chains at one end in order to co-operate with the teeth in maintaining the separation of the slats'a-nd in reversing their positions as they descend from one chain to the next,

I am aware that numerous driers have been constructed for the drying of fruits and similar materials in which endless aprons are employed with and without intermediate screens, and I do not therefore claim, broadly, a series of endless conveyers; but I believe myself `to be the first to 'produce a drier adapted for practicallyhandling lumber and containing the peculiarities above referred to and hereinafter described in detail.

In the accompanying drawings, Figure l is a longitudinal vertical section through a drykiln constructed in accordance with my invention. Fig. 2 is a vertical cross-section illustrating more particularly the manner of driving the chain. Figs. 3 and 4 are views showing alternative arrangements of gearing for driving the chains.

Fig. 5 is a top plan View of the same, the roof or covering being 5o removed.

Referring to the drawings, A is the kilnhouse or drying-chamber--a plain elongated building of a width equal to the length of the material to be dried and of'a height sufficient 55 to accommodate the number of chains orconveyers required. The walls and roof of the chamber should be built sufficiently close to prevent undue escape of the heated air. Within the building, one above another, I 6o arrange three pairs of longitudinal endless chains I, provided with carrying-teeth L. 'The two chains of each pair are arranged side by side in parallel lines at such distance apart as to give proper support to the lumber laid transversely upon them. Each pair of chains is sustained at its opposite ends by sprocketwheels mounted on horizontal shafts after the manner commonly practiced in similar structures. The chains may also be supported 7o by underlying wheels U, arranged at suitable intervals between their ends.

It is to be observed that the chains, instead of being arranged in horizontal positions, are arranged at an upward inclination from the receiving end at the left side of the apparatus to the delivery end on the right of the apparatus, this inclination of the chains being an essential feature of my invention. Be-

neath each chain I fix firmly in position a rail 8o K, commencing at the receiving end of the kiln and extending thence to the opposite end, Where. it is curved upward around and over the chain, as plainly shown in Fig. l. These rails lie so negar the ends of the teeth as to confine the lumber between the teeth.

At the receiving end of the kiln I mount a pair of inclined feeding-chains B, carried at their upper and lower ends vby suitable sprocket-wheels and extending at their upper 9o ends around the wheels which carry the upper chains of the series.

Motion may be communicated to the chains by mechanism of any suitable character. A simple arrangement is that shown in Figs. 1, 2, and 5, in which F F represent worm-wheels driven by worms I-I, mounted on vertical shafts G, which latter are connected at their lower ends through miter-gears with a horizontal shaft M, which may receive motion from any suitable source.

In operating the apparatus the interior of the chamber is heated by the introduction of hot air, by the use of a steam-coil, or by any other means known in the art and commonly used at the present dayin dry-kilns. The chains are then set in motion, the teeth on their upper sides traveling upward from the receiving toward the delivery end. The lumber to be dried is laid upon and between the teeth of the feed-chain B, by which it is delivered to the teethof the upper conveyerchains. These teeth, which maintain a separation of the material so that the hot air may circulate freely between and around the same, carry the material at the rising movement to the opposite end of the machine, ,Where it passes downward with the chain inside of the curved end of the rail K. This rail, holding` the pieces between the teeth, prevents them from falling one upon another, or, in other words, it maintains the separation of the pieces, which are carried downward and delivered on the upper or elevated ends ofthe underlying rails, down which they are carried by the action of the teeth, until the pieces are finally delivered one after another to the next succeeding chain, which carries them upward and delivers them in turn to the chain below.

It is tobe observed that owing to the curvature of the rails closely around t-he descend ing end of the chain the boards or strips are inverted, or, in other words, turned over, in their descent from the teeth of the chain to the rails thereunder. Thus it will be seen that the surfaces of the boards or strips which were uppermost during their movement to the right are turned down and subjected to the direct action of the ascending air-currents during the movement to the left.

The inclination of the chains and rails is advantageous, in that it permits the material to be carried downward over the rails with a comparatively small expenditure of power. Owing to the great width of the material which this apparatus is intended to handle, the friction of the material upon horizontal rails would be such as to necessitate the application of an objectionable amount of power. Owing to the inclination here described, it becomes possible to move the material upward upon the chains and downward upon the rails without difficulty.

It is to be particularly observed that in my apparatus three results are secured: first, the constant separation of the material under treatment to permit a free circulation and action of the air; second, the inversion of the material in a positive manner as it changes its direction of movement, and, third, the easy movement of the heavy material.

I prefer to sustain the chains at the top by underlying pulleys j, to prevent them from sagging under the weight of the lumber.

Instead of employing the driving-gearabove described, I may, as shown in Fig. 3, connect each of the chain-wheel shafts with a motorgear by a vertical driving-shaft G; or the chain-wheel shafts D may be provided, as shown in Fig. et, with spur-pinions connected by intermediate idle-pinions. As before observed, these driving devices are similar to those commonly used in the art and are not lof the essence of my invention.

Having thus described my invention, what I claim is l. In a kiln for drying lumber, endless toothed conveycr-chains having an upward inclination from their receiving to their delivery ends, in combination with rails closely underlying said chains and carried upward around the delivery end of the chains,whereby the boards or strips under treatment are inverted in passing from the upper to the lower side of the chains, their constant separat-ion maintained, and their easy delivery over the rails effected.

2. In a kiln for drying lumber, a pair of endless toothed chains arranged side by side, in combination with rails closely underlying said chains and carried upward closely around 'the delivery ends of the chains, whereby the separation of the boards or strips is maintained during their movement along the top of the chains, their inversion effected during their delivery to the underlying rails, and

their movement along the rails secured while loo their separation is maintained. I Signed at Ottawa this lst day of February, 1890.

VARREN SPEAR MAYO.

In presence of- A. J. CHRISTIE, EDW. O. RAFER. 

